1 Division of Microbiology and Risk Assessment, National Food Institute, Technical University of Denmark2 National Food Institute, Technical University of Denmark3 Sektion for Eksotiske Virussygdomme, Division of Virology, National Veterinary Institute, Technical University of Denmark4 Division of Virology, National Veterinary Institute, Technical University of Denmark5 National Veterinary Institute, Technical University of Denmark6 Section of Poultry Diseases, Division of Poultry, Fish and Fur Animals, National Veterinary Institute, Technical University of Denmark7 Division of Poultry, Fish and Fur Animals, National Veterinary Institute, Technical University of Denmark8 Section for Veterinary Diagnostics, Division of Veterinary Diagnostics and Research, National Veterinary Institute, Technical University of Denmark9 Division of Veterinary Diagnostics and Research, National Veterinary Institute, Technical University of Denmark10 Section for Veterinary Epidemiology and public sector consultancy, Division of Veterinary Diagnostics and Research, National Veterinary Institute, Technical University of Denmark11 Department of Applied Mathematics and Computer Science, Technical University of Denmark12 unknown